Materials - The p-n diode structure for selective UV detectors

The p-n diode structure for selective UV detectors

Description

The UV detector is based on p-n diode heterostructures, where gallium nitride GaN was used as a n-type layer and ZnO as a p-type layer. Both materials are transparent for visible light. The detector uses commercial GaN/Al2O3 substrate and ZnO layers made by molecular beam epitaxy (MBE) doped with group V elements (arsenic, nitrogen, antimony). The resulting structure is highly selective for detection of UV light and the detection is possible within the range of 350-375 nm. It is also possible to detect without an applied external voltage. The difference between the dark current and light current is 3-4 orders of magnitude.

 

Specification

  • Max detection 362 nm FWHM 12 nm
  • Iuv/Idark ~103-104
  • Open voltage 1.5-3 V
  • Break voltage higher than 20V
  • Reaction time ≪1ms

 

Applications

The UV detectors can be used for y environment protection, for example in detecting the presence of compounds of Aquatic oil. Such systems are often used to monitor leaks in the refueling of aircraft on aircraft carriers. Detectors can be used to build lines and matrices for selective detection of different wavelengths of the UV radiation.

 

Patent application: P.403520, P.399789

Current-voltage characteristics without and with UV illuminations.

Photocurrent measured with different reverse voltage.

Response of the detector to the pulse of UV light around max detection.